Method for broadcasting a magnetic stripe data packet from an electronic smart card

ABSTRACT

Method for broadcasting a magnetic stripe data packet from an electronic card by measuring a swipe speed of the electronic card past a magnetic reader head during a swipe of the electronic card past the magnetic reader head and then adjusting a broadcast signal containing the magnetic stripe data packet according to the measured swipe speed so that the magnetic stripe data packet in the broadcast signal is read by the magnetic reader head during said swipe.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Ser. No. 12/944,504,filed Nov. 11, 2010, which was a continuation-in-part application ofU.S. patent application Ser. No. 12/822,031, filed Jun. 23, 2010, thedisclosures of which are specifically incorporated herein by reference.The present application is also a continuation-in-part of U.S. patentapplication Ser. No. 13/102,991, filed May 6, 2011, which is acontinuation of U.S. Ser. No. 12/726,868, now issued as U.S. Pat. No.7,954,724, which was a continuation application of U.S. Ser. No.11/413,595, filed Apr. 27, 2006, which was a continuation-in-partapplication of U.S. Ser. No. 11/391,719, filed Mar. 27, 2006 and whichalso claimed the priority benefit of U.S. Ser. No. 60/675,388, filedApr. 27, 2005, all of which are specifically incorporated herein byreference.

FIELD OF THE INVENTION

The present invention is in the field of electronic smart cards, andmore particularly to an electronic smart card that can broadcast amagnetic stripe data packet so that it can be read by a magnetic cardreader during a swipe of the electronic card.

BACKGROUND OF THE INVENTION

The United States primarily relies upon credit and debit cards having noelectronics that are readable by a magnetic stripe card reader. Outsidethe United States, many countries rely upon smart cards that do notcontain a magnetic stripe but are readable by smart card readers. Eachoption has its advantages and disadvantages, and there are many reasonswhy both cards currently exist.

It has long been desired to create a single card usable both inside theUnited States with magnetic stripe readers and outside the United Stateswith smart card readers that offers the advantages of both cards whileminimizing the disadvantages of both cards. Such a card not only has thepromise of saving billions of dollars a year in fraud, but it also hasthe promise of opening many other uses for the card, and generatingenormous savings related to combining multiple cards into a single card.Yet, to date, it does not exist.

The prior art includes many patents that propose just such a card, butnone has yet been commercialized. Given the long felt need for such acard, and the enormity of the problems it could solve, and the attemptsby a great many to solve the problems associated with creating such acard, one has to ask why such a card is not yet available. The reasonsare many. Cost and manufacturability are two primary reasons why such acard has not yet been commercialized, but there are other reasons aswell. Such reasons include, but are not limited to, reasons relating tosecurity, privacy, standards, and several other issues that must beaddressed before such a card can be widely deployed.

The present invention recognizes and solves a problem that has preventedelectronic smart cards from broadcasting a magnetic stripe data packetreadable by a magnetic card reader during a swipe of the electronic cardpast a magnetic reader head.

SUMMARY OF THE INVENTION

The present invention is generally directed to a method for broadcastinga transaction specific magnetic stripe data packet from an electroniccard by measuring a swipe speed of the electronic card past a magneticreader head during a swipe of the electronic card past the magneticreader head and then adjusting a broadcast signal containing themagnetic stripe data packet according to the measured swipe speed sothat the magnetic stripe data packet in the broadcast signal is read bythe magnetic reader head during said swipe and the swipe speed ismeasured by a passive sensor.

The swipe speed is measured by a passive speed sensor. The passive speedsensor (which can be made of a quantum tunneling composite) can eitherbe a combination of outer and inner passive sensors placed across track1 and track 2 locations of the electronic card or the inner passivesensor can be placed along the track 1 location or the passive speedsensor can be a single passive sensor either placed along the track 1location or across the track 1 and track 2 locations.

The broadcast signal is adjusted by varying a current used to broadcastsaid broadcast signal, the magnetic stripe data packet can have a track2 data packet and/or a track 1 data packet and cross talk in themagnetic reader head is prevented by use of a cross talk blocker such asa piece of magnetic tape located on the electronic card so as to preventcross talk.

The electronic card is first activated from an off state to a sleepmode, then converted to an active mode after a wake up sensor isactivated during a swipe of the electronic card past a magnetic readerhead, and then the swipe speed of the electronic card past the magneticreader head during the swipe is measured and used to adjust a broadcastsignal containing a magnetic stripe data packet which is broadcastduring the swipe so that the magnetic reader head reads the magneticstripe data packet. False swipe detection can be prevented by measuringmovement past an outer detection point and an inner detection point of acapacitive sensor used to measure swipe speed. The broadcaster does notneed to be activated until the electronic card is in the active mode.

Accordingly, it is a primary object of the present invention to providea method for broadcasting a magnetic stripe data packet from anelectronic card so that it is read by a magnetic card reader during aswipe of the electronic card.

This and further objects and advantages will be apparent to thoseskilled in the art in connection with the drawings and the detaileddescription of the invention set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the back side of an electronic smart card in accordancewith the present invention with a back cover removed and certaincomponents shown diagrammatically on a printed circuit board (“PCB”).

FIG. 2 depicts the back side of an electronic smart card in accordancewith the present invention with a back cover in place.

FIG. 3 depicts a front side of an electronic smart card in accordancewith the present invention with a front cover in place.

FIG. 4 depicts an alternative arrangement of a back side of anelectronic smart card in accordance with the present invention with aback cover in place.

FIG. 5 depicts a trip switch used in a preferred embodiment of thepresent invention looking down onto a PCB on which the trip switch isconstructed.

FIG. 6 is a cross sectional view of the trip switch taken along view 6-6of FIG. 5.

FIG. 7 illustrates the electronic functioning of the trip switch of FIG.5.

FIG. 8 depicts a speed sensor used in a preferred embodiment of thepresent invention looking down onto a PCB on which the speed sensor isconstructed.

FIG. 9 is a cross sectional view of the speed sensor of FIG. 8 with arepresentation of a reader head pressing against the speed sensor duringa swipe.

FIG. 10 illustrates the electronic functioning of the speed sensor ofFIG. 8.

FIG. 11 illustrates the charge transfer working principal used incapacitive sensors.

FIG. 12 illustrates a processor or micro controller measuring the numberof charge transfer cycles and determining the speed of a card swipeusing the touch-profile method.

FIG. 13 illustrates a capacitive/swipe sensor's touch profile(right/left side pad) generation when a reader head travels over acapacitive sensor pad situated at left/right side of an electronic smartcard according to a preferred embodiment of the present invention. Note,however, in an actual case, the capacitive sensor pad on the cardtravels over the reader head.

FIG. 14 is a flow chart illustrating the steps of a preferred embodimentin which a broadcaster is activated by use of sensors.

FIGS. 15-18 illustrate four different designs of passive sensorconfigurations that can be used to detect the speed of a card swipe.

DETAILED DESCRIPTION OF THE INVENTION

As this application is a continuation-in-part application which includesimprovements over the inventions described in an earlier application,the original inventions will be described first, and then the newimprovements will be disclosed.

The inventions will now be discussed in connection with one or morepreferred embodiments shown in the Figures. In the Figures and thefollowing more detailed description, numerals indicate various featuresof the invention, with like numerals referring to like featuresthroughout both the drawings and the description. Although the Figuresare described in greater detail below, the following is a glossary ofthe elements identified in the Figures.

-   -   1 electronic smart card    -   2 printed circuit board (PCB)    -   3 extra piece of PCB added to PCB 2    -   5 front cover of card 1    -   6 back cover of card 1    -   15 front side of card 1    -   16 back side of card 1    -   20 trip switch    -   21 distance between extra PCB pieces needed to complete        electrical trip switch 20    -   22 extra piece of PCB added to PCB 2    -   23 electrical trace    -   24 extra piece of PCB added to PCB 2    -   25 extra piece of PCB added to PCB 2    -   26 electrical trace    -   27 extra piece of PCB added to PCB 2    -   30 capacitor speed sensor    -   31 outer detection pad    -   32 inner detection pad    -   33 piece of PCB added to PCB 2    -   34 conductive pad    -   40 broadcaster    -   40T broadcaster coil terminal    -   43 strip of magnetic tape    -   50 electronics    -   51 processor or micro controller unit (MCU)    -   60 battery    -   61 capacitive sensor    -   62 capacitive sensor    -   63 capacitive sensor    -   64 on/off button    -   65 7816 chip plate    -   66 security hologram    -   67 signature strip    -   71 account number    -   72 account number    -   73 account number    -   74 expiration date and CVV for account number 71    -   75 expiration date and CVV for account number 72    -   76 expiration date and CVV for account number 73    -   77 light emitting diode (LED)    -   81 branding    -   82 embossed primary account number    -   83 embossed user name    -   84 embossed expiration date    -   100 reader head    -   101 outer passive sensor    -   102 inner passive sensor    -   103 single thin passive sensor    -   104 single wide passive sensor

The original inventions provide for a method for broadcasting a magneticstripe data packet from an electronic card so that it is read by amagnetic card reader during a swipe of the electronic card. As noted inthe original application, a preferred embodiment of the originalinventions provides an electronic smart card, shown generally as 1 inFIG. 3, having a printed circuit board (PCB) 2 enclosed within a frontcover 5 on a front side 15 and a back cover 6 on a back side 16. Backside 16 of card 1 is orientated such that it functions similarly to aback side of a conventional credit card having a magnetic stripe on itsback side.

Electronic smart card 1 should be usable in situations where a smartcard reader is used and in applications where a card is read by aconventional magnetic stripe reader. Accordingly, electronic smart card1 should satisfy the ISO 7816 standard for smart cards, incorporatedherein by reference, and the ISO 7810 standard for transaction cards,also incorporated herein by reference. Details relating to both ISOstandards and electronics, dimensions and other details needed to meetboth standards, is set forth in U.S. Patent Application Publication20070034700, published Feb. 15, 2007, entitled “Electronic cards andmethods for making same,” the disclosure of which is specificallyincorporated herein by reference and hereinafter referenced as“Electronic Cards.”

Electronic smart card 1 should have two processors or micro controllersfor performing secure and non-secure functions as detailed in ElectronicCards. Alternatively, a single processor or micro controller can be usedto replace the secure and non-secure processors described in ElectronicCards so long as it has suitable input/output ports and divided memoryso that it functions equivalently to the secure and non-secureprocessors described in Electronic Cards. For purposes of the presentinvention, it will be presumed that MCU 51 is such a combined processoror a combination of a secure and non-secure processor as described inElectronic Cards.

Processor or micro controller unit 51 (whether it be a single processoror a combination of two processors) is mounted to PCB 2 as are otherelectronics, generally designated as 50, necessary for electronic smartcard 1 to function. Details of electronics 50 are not critical to thepresent invention and should be well within the skill of a person ofordinary skill in the art, especially when viewing the teachings ofElectronic Cards and the teachings of the present invention.

Front side 15 of electronic smart card 1 (see FIG. 3) has a 7816 chipplate 65 and can having branding 81, an embossed primary account number82, an embossed user name 83 and embossed expiration date 84. Embossedprimary account number 82, embossed name 83 and embossed expiration date84 are located according to the ISO 7816 standard and meet itsrequirements.

Back side 16 of electronic smart card 1 (see FIG. 4) has a signaturestrip 67 and hologram 66 that satisfy the ISO 7816 standard (likeconventional transactions cards). However, unlike conventionaltransaction cards, electronic smart card 1 has three capacitive sensors(61-63) for accessing three different accounts whose account numbers(71-73) and combined expirations dates with CVV (74-76, respectively)are printed on back cover 6. LEDs 77 alongside sensors 61-63 indicate toa user which, if any, of account numbers 71-73 has been selected foruse. (Note that in an especially preferred embodiment account number 71is the same as embossed primary account number 82 and embossedexpiration date 83 is contained in expiration date with CVV 74.) Alsoaccessed from back side 16 is an on/off switch 64. A strip of magnetictape 43 is also located on back cover 6 and positioned so as to preventcross talk between a reader head that can detect both track 1 and track2 data from a conventional magnetic stripe. Such positioning is keyed tolocation of where track 1 and track 2 data would be in a conventionalmagnetic stripe card following ISO standard 7810 and is thus locatedbetween where such data would be in such a card.

Electronic smart card 1 of the present invention uses a broadcaster 40for broadcasting a broadcast signal during a swipe of the card so that amagnetic stripe reader head can read a magnetic stripe data packetcontained in the broadcast signal. The broadcast signal may containtrack 1 and/or track 2 data (or, if desired, track 3 data as well). Thepresent invention is not concerned with details of a broadcaster,although such a broadcaster can actually take the form of separatebroadcasters so that a given broadcaster only broadcasts the data for agiven track of data as is explained in greater detail in ElectronicCards. It should be noted, however, that it has been found that theproblem of cross talk (discussed in greater detail in Electronic Cards)can be effectively dealt with by use of a magnetic stripe positioned onback cover 6 as already noted above. This method of dealing with crosstalk is much simpler, cheaper to implement and more efficient thanbroadcasting a cancellation signal to prevent cross talk and representsa significant advance in the prevention of cross talk in an electroniccard that broadcasts data to a magnetic stripe reader head.

Attached to PCB 2 oriented toward back side 16 of card 1 are two wake upsensors in the form of trip switches 20 and two speed sensors 30oriented toward the side ends of card 1 in the proximate area of card 1where a magnetic stripe is located in a conventional magnetic stripecard according to ISO standard 7810. Two wake up sensors and speedsensors are included so that electronic card will function when read bya magnetic stripe reader in either a left to right or right to leftswipe direction.

Each wake up sensor or trip switch 20 is located such that it will betriggered by a magnetic reader head 100 during a swipe of electronicsmart card 1 before magnetic reader head passes over any portion ofbroadcaster 40 FIGS. 5-7 depict a wake up sensor in the form of tripswitch 20. Trip switch 20 functions as a simple on/off switch that istriggered when magnetic reader head 100 passes over it. In an especiallypreferred embodiment, trip switch 20 has two PCB pieces 23 and 25connected by trace 24 built upon PCB 2 and a second set of two PCBpieces 26 and 28 connected by trace 27 also built upon PCB 2. Two setsof PCB pieces are used to ensure that reader head 100 passes over one ofthe sets (of course, a larger set of PCB pieces could be used, but itwould be less efficient and more expensive). The distance 21 between thetwo sets of PCB pieces 23/25 and 26/28 is less than the width ofmagnetic reader head 100 so that trip switch 20 will be triggered asmagnetic head 100 passes over it. FIG. 7 shows a conceptual diagram ofthe function of trip switch 20. Each trip switch 20 is electricallyconnected to MCU 51. MCU 51 is triggered to an active mode when itreceives an activation signal from one of trip switches 20.

Although electronic smart card 1 can function without use of wake upsensors, they are included in an especially preferred embodiment becausethey help to prolong the life of battery 60. Because electronic smartcard 1 uses a broadcaster 40, broadcaster 40 will consume energy frombattery 60 when it is in an active mode. When a user activateselectronic smart card 1 by turning it on through on/off button 64,electronic card 1 will be consuming energy from battery 60. However,through use of trip switches 20, broadcaster 40 will remain in a sleepmode and not be powered up into an active mode until one of tripswitches 20 is activated, thus minimizing power consumption bybroadcaster 20.

Speed detection is critical for MCU 51 of electronic smart card 1 todetermine the rate of broadcast by broadcaster 40. There are variousways of determining the speed of card 1 travelling across a reader head,such as photo sensor. However, it is especially preferred that acapacitive sensor is used for speed detection because it offers theadvantages of a very low profile, relatively low cost and relatively lowpower consumption.

Each speed sensor 30 is located such that it will be triggered bymagnetic reader head 100 after it has activated a trip switch 20 andbefore magnetic reader head 100 passes over that portion of broadcaster40 that conveys a broadcast signal to magnetic reader head 100 during aswipe of electronic smart card 1. Although speed sensors 30 can takedifferent forms, in an especially preferred embodiment, each speedsensor 30 is comprised of a capacitive sensor having an inner detectionpad 31 and an outer detection pad 32, the outer detection pad beingcloser to the outside side edge of card 1. Outer and inner detectionpads 31 and 32 are comprised of PCB pieces 33 and a conductive layer ofmaterial 34 (such as copper or silver). The purpose of PCB pieces 33 isto move conductive layer of material 34 up closer to reader head 100.Outer and inner detection pads 31 and 32 are electrically connected toMCU 51.

Capacitive speed sensors 30 work based on the principle ofcharge-transfer signal acquisition for robust sensing. The acquisitionmethod charges a conductive layer of material (or pad) 34 of unknowncapacitance (Cx) to a known potential. The resulting charge istransferred into a measurement capacitor (Cs). The charge cycle isrepeated until the voltage across Cs reaches the required voltage. Thenumber of charge-transfer cycles it takes to reach a voltage (Vih) iscalled signal level of measurement capacitor Cs. Placing a finger on thetouch surface introduces an external capacitance (Ct) that increases theamount of charge transferred each cycle and hence it reduces the signallever/number of transfer cycles required for Cs to reach the voltage.When the number of cycles reduces more than the present threshold, thenthe sensor is reported as in detect whereas the sensor identifies afalse detect when the number of cycles exceeds the present threshold.

Based on the charge transfer principle, the dielectric of the capacitoris the material between the magnetic reader head and pad 34. In anembedded design, dielectric of the capacitor is formed by overlay andFR4 material whereas in a chip plate design, dielectric of the capacitoris formed by the overlay alone. In both designs, the conductive padforms one of the electrodes of a capacitor. The magnetic reader headacts as the other electrode of the capacitor, which also provides avirtual ground to the resulted capacitor. This is shown in FIG. 12.There are two different especially preferred designs for a capacitivesensor useful in the present invention as a swipe speed detectionsensor. The first design is using a copper pad embedded on a top siderear of main PCB 2 and the second design is using a 0.4 mm thick chipplate PCB to elevate the copper pad off of top side rear of main PCB 2as shown in FIG. 8.

Keeping the sense capacitance value (C_(s)) unchanged, the separationbetween the magnetic reader head and the capacitive sensor is criticalfor the sensitivity of the capacitive sensor. The larger the separation,the less sensitive the capacitive sensor it is. Comparing the twodesigns, the separation between the magnetic reader head and thecapacitive sensor is 0.075 mm in the chip plate design of FIG. 8. Thisis a much smaller gap distance as compared to approximately 0.5 mmseparation distance in the embedded pad design. Therefore, it isexpected that the capacitive sensor in the chip plate design has bettersensitivity as compared to that in the embedded pad design.Nevertheless, the embedded pad design is simpler as compared to the chipplate design.

The firmware implementation for swipe speed, inch per second (S_(ips)),detection will be based on the time stamps, T₁ and T₂, marked at theedges of the sensor's touch profile, which is generated when the readerhead travels over the capacitive sensor pad of length L_(pad). It isimportant that the detection method is independent of the magneticreader head. This is because the capacitance and the dimension of themagnetic reader head are different from one reader head to another. Thetouch-profile method depends only on the length of the sensor pad andany variation of the magnetic reader head will not affect the speeddetection accuracy. Hence, the swipe speed in inches per second(S_(ips)) is calculated as:S _(ips) =L _(pad)/(T ₂ −T ₁)  Equation 1The sequential flow of firmware in SWIPE state (see FIG. 14) is detailedas:

-   -   A non-secure chip shall be put into deep sleep mode until it is        woken up by the wake up source, WDT timeout/External interrupt,        to transition into active/normal state.    -   If the chip is woken up by WDT timeout then it checks for Swipe        Long Timeout elapse and enters back to sleep mode until the        swipe timeout elapse.    -   If the chip is woken up by an external interrupt source, from        one of the trip switch/sensors populated at either side of the        card, which in turn decides the direction of the swipe, enables        the swipe/capacitive sensor touch profile capture for speed        detection until Swipe Short Timeout elapse.    -   As shown in the above, FIG. 13, the difference count from        reference to touch is dynamically monitored until the difference        count reaches the maximum, where the time stamp T₁ is marked.        The time stamp T₂ shall be marked when the difference count        starts decreasing from its maximum value.    -   The swipe speed in inch per second (S_(ips)) will be calculated        based on the profile time stamps and capacitive sensor pad        length by using Equation A.    -   The swipe speed calculated shall be compared with minimum,        medium and maximum speed threshold levels to decide the        broadcast data rate through coil terminals. It is especially        preferred that there be three discrete levels to broadcast data        by broadcaster 40 based on the detected speed:        -   a) Slow 5 IPS≦Swipe Speed<10 IPS, data rate=3750 bits/sec        -   b) Medium 10 IPS≦Swipe Speed<20 IPS, data rate=7500 bits/sec        -   c) Fast Swipe Speed≧20 IPS, data rate=10000 bits/sec    -   Although the data transmission rate changes according to        different swipe speed range, the read amplitude remains        constant. If swiping a conventional mag-stripe card at the speed        of 50 IPS produces read amplitude of 3Vp-p, then electronic        smart card 1 will produce the same read amplitude regardless of        swipe speed and broadcast card with the MCU will produce read        amplitude of 6Vp-p.    -   If the set data rate is within the boundary condition, the swipe        state will be transitioned to BROADCAST state by        ‘gSwipe2Broadcast( )’ function.        After BROADCAST state, the chip enters back to SWIPE state until        the Swipe Short Timeout elapse.

The Detailed Description of the Invention so far has set forth what wasdisclosed in the earlier application of which this is acontinuation-in-part. What follows are additional disclosures and newinventions that build upon the original disclosure. The capacitivesensor set forth in the earlier application is an example of an activesensor. An active sensor is characterized by the fact that it operatesin an active mode consuming energy while it is waiting to be used todetect speed. Examples of other active sensors that might be usedinclude a Hall-effect sensor or an inductive sensor.

It is also possible to use passive sensors as speed sensors to measureswipe speed. In contrast to an active sensor, a passive sensor usespressure/force to activate the sensor which behaves like an on/offswitch. When unstressed, the passive sensor behaves like an insulator,having very high resistance, acting as an opening circuit electrically.When stressed, the resistance of the sensor reduces and behaves like aconductor, acting as a short circuit electrically.

An advantage of using a passive sensor to detect swipe speed is lowerenergy consumption. Unlike an active sensor, the passive sensor does notconsume energy in an active state waiting to detect speed, which alsomeans that it does not require a wake up switch to turn it on andprepare it to detect swipe speed.

In an especially preferred embodiment, the passive sensor can use aquantum tunnelling composite (“QTC”) such as is available from PeratechLimited of the UK. As is explained in the website for Peratech Limited,QTC is new class of electrically conductive material developed toadvance the capability of switching and sensing systems. QTC is anelectrically conductive material that has the ability to smoothly changefrom an electrical insulator to a metal-like conductor when placed underpressure. While in an unstressed state the QTC material is a nearperfect insulator, with any form of deformation the materials starts toconduct and with sufficient pressure metallic conductivity levels can beachieved. This means that QTC can be used as a solid state switch whichcan be used to detect even very small changes due to compression,tension or other stresses caused by the reader head as it moves over asmart card 1 according to the present invention. Additional detailsregarding a QTC switch are set forth in publication WO/2010/109186published Sep. 30, 2010, which was based upon patent applicationPCT/GB2010/000546, the disclosure of which is specifically incorporatedherein by reference.

It should also be noted that a passive sensor, preferably using QTC, canalso be used as a trip switch to activate an active sensor or to replacecapacitive sensors 61-63.

FIGS. 15-18 disclose four different designs of a smart card 1 that usesQTC sensors, instead of capacitive sensors, to detect the swipe speed.

In a first design shown in FIG. 15, two vertically parallel passivesensors 101 and 102 are placed next to each terminal 40T of broadcaster40, across Track1 and Track2 locations. When the magnetic reader headpasses the two sensors, it activates the sensors one by one. Bymonitoring the time elapsed between the two activations, swipe speed canbe calculated. To broadcast the data, a software delay can be introducedin order to avoid the low flux area along the broadcaster coil terminal40T. Since swipe speed detection depends on the time between T₁ and T₂,it requires the sensor to have fast response time in order to have twodistinct pulses due to the activation of the sensors. The swipe speed ininches per second (S_(ips)) is calculated as:S _(ips) =D _(S)/(T ₂ −T ₁)  Equation 2where D_(S) is the distance between the two sensor points S₁ and S_(2.)Note that while sensor points S₁ and S_(s) are shown in FIG. 15 as beingat the inward side of the edges of parallel passive sensors 101 and 102,they need not be located only at this point, as long as the correctlocation is taken into account in the software calculations. Moreparticularly, the software calculations will calculate when thebroadcast signal should be broadcast based upon the calculated swipespeed and necessary time delay, and the software will calculate thefrequency of the broadcast signal so that it will not miss the read headduring the swipe.

In a second design shown in FIG. 16, the outer passive sensor 101 isstill placed across Track1 and Track2 locations, but the inner passivesensor 102 is placed along Track1 location, above the broadcaster 40.One advantage of this component placement scheme is that it will allowthe data broadcasting to take place essentially immediately after innersensor 102 becomes an open circuit and a programmed software delay is nolonger required because the reader head will be beyond broadcaster coilterminal 40T due to placement of inner passive sensor 102. Anotheradvantage of this component placement scheme is that the distancebetween inner and outer passive sensors 101 and 102 is greater which canlead to more accurate speed measurement. Again, since swipe speeddetection depends on the time between T₁ and T₂, it requires the sensorto have fast response time in order to have two distinct pulses due tothe activation of the sensors. In this scheme, sensor point S₁ is shownin FIG. 16 as being at the inward side of the edge of parallel passivesensor 101, although it need not be located only at this point, as longas the correct location is taken into account in the softwarecalculations. By contrast, it is useful for sensor point S₂ shown inFIG. 16 to be located at the inward side of the edge of parallel passivesensor 102 in calculating the software delay introduced in order toavoid the low flux area along the broadcaster coil terminal 40T. In thisscheme, the software calculations will calculate when the frequency ofthe broadcast signal so that it will not miss the read head during theswipe.

In a third design shown in FIG. 17, a single passive sensor 103 isplaced next to each side of the broadcaster coil and it is along theTrack1 location. The inner edge of the sensor can be used to trigger thedata broadcasting. The time taken from the instant the magnetic readerhead touches the outer edge of the sensor to the instance it leaves thesensor will be used to calculate the swipe speed and a programmedsoftware delay to avoid broadcasting along broadcaster coil terminal 40Tis not required. Requirement of the sensor response time is lessstringent as compared to the first and second designs as the length ofthe sensor in this design is much longer and the rise time and fall timeis insignificant as compared to (T₂−T₁). The swipe speed in inches persecond (S_(ips)) in this scheme is calculated using Equation 1 in whichL_(pad) is replaced by L_(sensor) and L_(sensor) represents the lengthof passive sensor 103.

In a fourth design shown in FIG. 18, a larger passive sensor 104 isplaced next to each side of the broadcaster 40 and it covers all thetrack locations. This design has the advantage of ensuring betteractuation area between the magnetic reader head and the sensor and thewidth of the sensor is matching the width of the magnetic reader head.However, a software delay is required in this design in order tobroadcast the data after the low flux region along the broadcaster coilterminal 40T. The swipe speed in inches per second (S_(ips)) in thisscheme is calculated using Equation 1 in which L_(pad) is replaced byL_(sensor) and L_(sensor) represents the length of passive sensor 104.

While the invention has been described herein with reference to certainpreferred embodiments, those embodiments have been presented by way ofexample only, and not to limit the scope of the invention. Additionalembodiments thereof will be obvious to those skilled in the art havingthe benefit of this detailed description. For example, the presentdisclosure and FIGS. 2 and 4 illustrate an electronic smart card havingthree different visible account numbers, whereas additional accountnumbers could be added. Also, a visual display device could be added fordisplaying the account chosen by a user. Further modifications are alsopossible in alternative embodiments without departing from the inventiveconcept.

Accordingly, it will be apparent to those skilled in the art that stillfurther changes and modifications in the actual concepts describedherein can readily be made without departing from the spirit and scopeof the disclosed inventions as defined by the following claims.

What is claimed is:
 1. A method comprising broadcasting a transactionspecific magnetic stripe data packet from an electronic card bymeasuring a swipe speed of the electronic card past a magnetic readerhead during a swipe of the electronic card past the magnetic reader headand then adjusting a broadcast signal containing the transactionspecific magnetic stripe data packet according to the measured swipespeed so that the transaction specific magnetic stripe data packet inthe broadcast signal is read by the magnetic reader head during saidswipe, wherein the swipe speed is measured by a passive speed sensor. 2.The method of claim 1 wherein the passive speed sensor is comprised ofan outer passive sensor and an inner passive sensor and both the outerpassive sensor and the inner passive sensor are placed across a track 1location and a track 2 location of the electronic card.
 3. The method ofclaim 2 wherein the broadcast signal is not broadcast until the magneticreader head has traveled beyond a broadcast terminal of a broadcaster ofthe electronic card.
 4. The method of claim 1 wherein the passive speedsensor is comprised of an outer passive sensor placed across a track 1location and a track 2 location of the electronic card and an innerpassive sensor placed along the track 1 location of the electronic card.5. The method of claim 1 wherein the passive speed sensor is comprisedof a passive sensor placed along a track 1 location of the electroniccard.
 6. The method of claim 1 wherein the passive speed sensor iscomprised of a passive sensor placed across a track 1 location and atrack 2 location of the electronic card.
 7. The method of claim 6wherein the broadcast signal is not broadcast until the magnetic readerhead has traveled beyond a broadcast terminal of a broadcaster of theelectronic card.
 8. The method of claim 6 wherein the broadcast signalis adjusted by varying bit rate used to broadcast said broadcast signal.9. The method of claim 1 wherein the transaction specific magneticstripe data packet is comprised of a track 2 data packet.
 10. The methodof claim 9 wherein the transaction specific magnetic stripe data packetis further comprised of a track 1 data packet.
 11. The method of claim10 wherein cross talk in the magnetic reader head responsible forreading track 1 data is prevented by use of a cross talk blocker. 12.The method of claim 11 wherein the cross talk blocker is a cancelationcoil located on the electronic card so as to prevent cross talk.
 13. Amethod, comprising: activating an electronic card from an off state to asleep mode; changing the electronic card from the sleep mode to anactive mode after a wake up sensor is activated during a swipe of theelectronic card past a magnetic reader head; measuring a swipe speed ofthe electronic card past the magnetic reader head during the swipe;using the swipe speed to adjust a broadcast signal containing atransaction specific magnetic stripe data packet; and broadcasting thetransaction specific broadcast signal during the swipe so that themagnetic reader head reads the magnetic stripe data packet.
 14. Themethod of claim 13 further comprising using a processor to generate thebroadcast signal once the swipe speed is measured.
 15. The method ofclaim 13 wherein the swipe speed is measured by an active sensor havingan outer detection point and an inner detection point.
 16. The method ofclaim 15 wherein a false swipe detection is prevented by measuringmovement past the outer detection point and the inner detection point.17. The method of claim 13 wherein a broadcaster in the electronic cardis activated during the active mode.
 18. The method of claim 17 whereinthe broadcast signal is adjusted by varying a bit rate used by thebroadcaster to broadcast said broadcast signal.
 19. The method of claim17 wherein the broadcaster is comprised of a track 2 broadcaster thatbroadcasts a track 2 data packet and a track 1 broadcaster thatbroadcasts a track 1 data packet.
 20. The method of claim 13 wherein across talk blocker is used to prevent the magnetic reader head fromreading a particular track data packet in a reading area of the magneticreader head that is not meant to read the particular track data packet.